USPS pursues the cheaper alternative to replace its aging fleet.

The Postal Service will soon begin adding more leased vehicles to its fleet, as a cash shortage has prevented it from purchasing new vans and trucks.

The decision marks a shift for the agency, which currently owns nearly all of the more than 211,000 vehicles in its fleet. USPS decided to begin leasing vehicles as “presently, there are not sufficient capital funds to purchase new equipment,” according to procurment documents posted to FedBizOpps.

The Government Accountability Office said in 2011 the Postal Service needed a strategy to address its “aging delivery fleet.” It confirmed, however, USPS could not afford to replace or refurbish a large portion of its vehicles. As the vehicles continued to get older, the maintenance costs associated with them continued to grow, GAO found.

Two years later, the Postal Service has finally reached a breaking point, and without the congressional action GAO called for, USPS has turned to increasing the use of leasing to replace old vehicles.

“Our vehicle delivery fleet is aging and we have been limited in our ability to do large scale vehicle purchasing because of our financial crisis,” said David Partenheimer, a USPS spokesman. “Vehicle leasing is one of the ways we are making sure we continue to have the fleet resources needed to deliver the mail in a timely manner while we continue to take action under our control to return to sound financial footing and urge for the passage of comprehensive postal reform legislation.”

The Postal Service included a $624 million proposal to purchase 24,000 new vehicles in its preliminary fiscal 2014 budget, though USPS officials said the request was unlikely to survive final prioritization.

The leasing solicitation announced the Postal Service will seek a contract to rent or lease, with the option to purchase “motor vehicles suitable for mail delivery,” such as minivans and cargo vans. USPS will sign a lease of up to three years.

The Postal Service said it initially anticipates a small need for leased vehicles, but expects the number to grow in the coming years as its fleet continues to age.